British Foreign Secretary William Hague said: “I condemn the incident in Homs today which caused the death of at least eight civilians.

"These deaths highlight once again the terrible price being paid by the people of Homs, as well as the courage of journalists who take great personal risks to bring to light what is happening to the people of Syria."

He added: “We call again on President Assad to step down and heed the will of the Syrian people."

Activists and opposition groups said that up to 24 people died across Syria on Wednesday as the crackdown against protesters continued.

Meanwhile the Arab League mission sent to monitor the country and ensure it halts the violence against civilians has delayed sending more observers after an attack on one of its teams.

Elsewhere, President Bashar al-Assad gave a second speech in two days to a cheering crowd in Umayyad Square in Damascus, saying that the "homeland was reeling under the brunt of conspiracy".

"Syrians will undoubtedly triumph over the conspiracy, which is nearing its end," Assad told the crowd, a day after assuring Syrians in a televised speech that "terrorists" would be met with an "iron fist".

The UN says that at least 5,000 people have been killed in Syria since the start of anti-government protests in March last year.